Retopology in Blender - Polybuild tool

hello blenderheads and welcome to this three-part series on retopology i decided to make these tutorials as there seems to be a lot of people in the blender forums who are really struggling with re topology now i think there's a couple of reasons for this firstly if you haven't done retopology before it's kinda hard you have to know about edge loops and edge flow and how to redirect polygons and just good topology in general the other reason is that blender maybe isn't the best retopology tool available now it works and it can work quite well but there's a few well i wouldn't go quite as far to call them bugs but some of the tools just aren't quite optimized for retopology so we'll talk about what they are and how to spot them when things go wrong and how to fix them in these tutorials so this series will be broken into three parts this first lesson will cover how to re-topologize a model using only blender's native tools our main tool of choice here will be the poly build tool in the second lesson we'll step up our game and introduce the speedry topo add-on which still uses blender's built-in tools but it packages them up into a nicer user interface and generally helps speed up your workflow quite considerably and then finally we'll look at the king of retopology and blender at the moment re-topoflow which appears to be using its own custom built tools and those kind of help us get around some of blender's shortcomings with the slight downside that ritopo flow is a paid add-on but more on that in part three now if you're completely new to retopology i recommend that you start with this video and re-topologize a couple of models say maybe three to five models before stepping up your game and getting into speedry topo now the reason for this is that retopology can be confusing enough without adding even more complicated tools that can break in even more complicated ways so get used to doing it slow and deliberately using these methods and then once you've got a firm grasp of what you're doing only then would i recommend stepping up your game with something more powerful so with that in mind let's jump in and see how we re-topologize using only blender's built-in tools for this tutorial i'm going to be using the spyro sculpt i did a little while back because i never bothered to re-topologize him properly and he's a relatively simple model that we can use for our example there'll be a link in the description where you can download your own copy of this model if you want to follow along at first glance you might think that this model looks okay until we go and turn on the wireframe and then you can see that this is just an absolute disaster now from memory i think i did an automatic retopology on this guy using instant meshes which is a standalone program which you can download for free to automatically re-topologize your models again i'll make sure there's a link in the description to instant meshes now if you just need something quick and dirty instant meshes can work quite well it allowed me to quickly re-apologize my mesh and just get on with the process of sculpting but you can see that this kind of strange almost honeycomb shaped topology here is it's just going to be completely useless for animation and it's also just ridiculously dense you just wouldn't want to animate with this your scene would slow down considerably so the first thing that we're going to want to do is create something to work as our re-topologized mesh so for that i'm going to create a plane let me see that mine's offset a little bit here i'm just going to go alt g and alt r to reset it back into the center just jump over to the right side here and let's rotate that 90 degrees just place this out the front and shrink it a little bit i'm going to start by doing his chest here so let's just kind of scale this down a little bit go to the front view scale it down a little bit more so that will kind of fit in these ridges and just shift it across so it's on one side maybe shrink it down a little bit further now some of the modifiers that we apply here do actually use distances in centimeters and millimeters or whatever so it's a good idea to apply all of our transforms here just in case that can mess things up a little bit so with our plane in place here let's go and start by adding a mirror modifier so that we only have to do one side of his body now if we drop into edit mode here i'm just going to tilt this so it's a little bit easier to see and turn off my proportional editing there so if i go and grab here you can see that these vertices are kind of crossing over that center point and we really don't want that that can that's just a bit of a pain to try and work with so we're going to start by turning clipping on here and now you'll see that those vertices can't go past that center line and in fact now that they're touching in the center we also can't pull them apart this is a much easier way to work next we want to set up our snapping so that these vertices will actually snap to our sculpted mesh over here so let's turn on snapping up here and drop down here and i found that face tends to work best for this kind of model if we just go back to our front view here and tap g we'll see that this now snaps to our sculpted mesh but you can see that it's not snapping particularly well we've got one vertices here that's kind of just delved inside of our mesh just go back to solid mode here these ones haven't attached properly at all now the reason for that let's just undo that is that it's projecting the entire face so it's kind of projecting from here and ignoring the edges we don't want that so if we go back to our snapping menu here we've got project individual elements if we turn that on just go back to the front view again and tap g you can see that's now snapping a little bit better now vertices are in fact snapping onto that mesh now it is still kind of penetrating inside of it a little bit so the best way to fix that is to add another modifier and let's go and add a shrink wrap just minimize that mirror modifier a little bit go and make our target the body here and my personal favorite for these settings here the wrap method i like to use project and the snap mode i like above surface and you can see here that that's kind of done some weird stuff that's because we need to have both positive and negative selected here and you can see that now snaps it back into place and we just want to add a little bit of offset here just until that kind of pops out the front in our case about 0.01 seems to work quite nicely you want to try and keep this offset as low as possible because the further you have it offset in fact you can kind of see that the shape of that distorts as we move it in and out so the further out we go the less accurate we become so keep this as low as possible another thing that can potentially mess up our shrink wrap modifier if we go over here to our overlays and turn on face orientation you can see that these faces on our new mesh here are red and the ones on our sculpted mesh are blue that tells us which way the normals are facing so blue means that it's facing towards us red means that it's facing away and if i just go and hide this you can see on the other side is where it's blue that's what we want facing us so if we just go back into edit mode and tap a to select all we can go shift n and that will recalculate our normals and pop them out the other side alternatively you can also go alt n and that brings up all of your normal options and you can go flip now you can also see that i've got my vertices down here but i kind of can't see the ones that are here they're not like they're not properly lining up to my mesh if we just go to our shrink wrap here and turn on cage you'll see that that suddenly becomes a little bit more visually accurate for us now a final couple of little things just to kind of help us visualize all of this let's start by turning off our face orientation and instead let's go to our viewport shading here and change this to random and i'm also going to go and turn off our wireframe because this sculpted mesh is just a little bit too dense so you can see now that we've got this random selected all of our meshes end up with this random kind of pastel color and that just makes it so much easier to be able to see in this case it's chosen green for us on top of blue that just makes it much much easier to be able to tell these meshes apart now one final thing and this one's optional if we zoom around to the back here you can see that we can still see the outline of our retapologized mesh but if we go down to our object properties and scroll down to viewport display we can also click in front and now it doesn't matter where we are on our model we can always see this re-apologized mesh now some people really like that setup personally i'm not a huge fan of it i find that a little bit visually confusing i kind of prefer to not be able to see it when it's behind my model personal preference try using both and see which one you prefer so that gets our scene set up let's actually now start using the poly builds tool so let's go into edit mode over here and select our poly build and you can see that i immediately start getting all of these little blue highlights all over my mesh so if you zoom in you can see that i can either get them on individual vertices which highlight this tiny little blue dot or i get the entire edge the vertices mean that i can click and drag and just reposition my vertices so let's go and kind of line this up a little bit better with kind of these ridges that we've created for the chest armor here and these blue lines on the edges tell us where we can extrude from so if i click and drag you can see that i can start to pull out some new edges and then i can come back and kind of redefine exactly where i want those vertices to sit now you can see that we're starting to get some of the mesh showing underneath a little bit of that's okay but we probably don't want this much so what's really nice about the polybuild tool is that it works in conjunction with all of these other tools so i can just come over here and grab whereas an insert loop and i can click there and you can see that that pops out and creates a new edge loop going through there but what's even nicer if i undo that and just go back to our poly builds tool if you know your keyboard shortcuts you don't actually need to change tool so i can go ctrl r and you can see that it now comes up with my little highlight there if i just click it goes and creates that edge i can scroll up and down or sorry move my mouse up and down to reposition it or i can right click to make sure that it snaps dead in the center and you can see that it's immediately gone back to my poly builds tool so even though i've just created that edge i can immediately start adding new edges without any problems and then i can go back to my insert edge loop and create another edge loop again without a problem let's say that i had this edge selected i can also go ctrl b and i can bevel it if i so choose in this case i don't think i want one there now you can see that in creating this i've also created this little bit of a gap and these vertices just don't automatically merge so i mean you might think the easy way is to kind of go back to your select tool select both of those hit m and merge them and that is one way of doing it but it's a little bit slow so if i just undo that and go back to our poly build tool alternatively we can go up to our tools here and under options we can check auto merge if you just drop that down you can see you've got a threshold here which tells you how close these vertices need to be before they will snap together and merge now this threshold depends on how big your model is in the scene generally speaking i try to work to real world units so i think spy right here is i don't know maybe three meters or something so i found that this by default most of the time is too low for me so i'm just going to go and delete one of those zeros and make it 0.01 and if i come in here and push these vertices close together you can see that they automatically snap and we've now merged those so now if i come down here i can just sort of extrude those and they will automatically snap to each other very very quickly and then i can go and add another edge loop through there and that's starting to look pretty good and we're getting a reasonably fast workflow now as well as just clicking and dragging so that we get these entire quads coming out we can also zoom in a little bit closer here get one of our edges and hold down control and you see that we start to get these triangles forming so with that you can just click let's just make sure that snaps to the center and you can very quickly start to create tries generally speaking you want to avoid them so now i can grab this edge and again control and i can pull out an entire quad now so it just it takes your tries and automatically tries to convert them to quads which is really really nice so that's okay for just coming down here and quickly creating new polygons but where i find it particularly useful is if you go into the corners here you can see that i get both of these these tries combining and creates a quad so if i just click you can see that i've now created a quad and i can drag that out or alternatively you can come in here and hold down control and click and then you can drag and just pull the whole thing out and this now allows us to work really really quickly so i can pull out an entire edge and then quickly snap down my next couple of vertices and this workflow starts to get very very fast and it's really nice now as well as the poly builds tool you don't have to be limited to just pulling out one quad at a time you can go back to your tweak tool here and if i just grab all of these edges along here and hit e for extrude you can see that i can pull out an entire loop all at once and then just kind of reposition that just be a little bit careful with how many edges or or vertices you pull out all at once if i just kind of get an angle here and extrude from here and try to pull out you can see i start to get this weird snapping off to the side there that's because it kind of projects from your view and here it doesn't quite know where on the neck it needs to wrap to so either make sure that you got your camera angle at a nice angle to be able to do that without it breaking or maybe just pull out certain edges at a time and just try to limit how much you try and pull all at once as that will help it to avoid breaking now speaking of things breaking i've got an alternative scene here which is almost exactly the same but if i jump into edit mode here you can see that i've got some vertices which are just not quite aligned nicely how we would like them so you'd think that this would be a fairly easy fix all you need to do is go and grab your vertice and tap g and move it to the middle but you can see that as i tap it all of these other vertices kind of pop in this really strange way and that's ultimately because of our shrink wrap modifier over here so if i just go and go back into object mode for a moment let's hide our body let's just disable our shrink wrap modifier and just kind of watch this area where these vertices have misbehaving you can see that they pop quite a long way into where our mesh usually is when it's not hidden if i turn that on and off a few times you can see that that's kind of what's going on there we expect it to pop a little bit just because of this offset but we don't want it to be popping that much so let's just bring back our main mesh here now in this case it's probably not too difficult to fix we kind of know that it's these vertices and if i just kind of grab all four of those you can see that we can very quickly fix it and the popping just kind of goes away but sometimes you won't know which vertices it is and it'll be happening across the whole mesh and that just becomes a little bit painful so what i've found is probably the fastest way to fix this is to just come over here to our shrink wrap modifier i'm going to duplicate it so we've kind of got a backup of it and then i'm going to apply this first one you can see that that has done a few different things first of all it's kind of screwed up our middle line here that's a little bit annoying if we hold down shift and alt and just click that edge it selects the whole thing and then we can just go scale on the x and just tap zero and that usually fixes it in this case i might also need to grab it on the x and just shift it back and forth a little bit and that snaps everything back to the middle but this has now kind of repositioned our vertices so if i go and hide this again and turn this on and off you can see that they're not popping massively inside of the mesh so this is actually more accurate to what we want it to be and now when we go into edit mode you can see that our popping has in fact disappeared [Music] and we can reposition these without that monstrous popping all over the place going on so if you start to run into problems don't be afraid to come back and just reapply your shrink wrap it can fix a whole range of different things okay so back over here in our original scene which admittedly doesn't look that much different i'm just going to go and add a few more edges through here so you can just kind of quickly see how fast we can kind of uh go through and redo our topology in particular i kind of want to show you how to read apologize this little area here you see we've got all of these little lumps and bumps and everything which your initial instinct may be to try and read topologize all of this i'm just going to throw it out there right now generally speaking i would not bother this is the sort of detail that you'll eventually want to pick up in either displacement or normal maps for doing your retopology for the most part you can just ignore all of these little lumps and bumps and in a later tutorial i'll show you how to set all of this up so you can just use maps to get this detail rather than trying to build it into your topology because trying to build it into your topology is an absolute nightmare and you'll end up with edges that kind of go everywhere whereas in we really want this nice these nice smooth quads that you can really just follow with your eye so let's just get a few more of these in and then i'll show you how you can test and see whether your read topology is actually working the way you want it so let's just kind of cover all of those and i think i want another edge loop going through here just to kind of make all of this a little bit more square don't forget that you can go into your tweak mode here and select an entire edge and if you tap double g you can slide edges along their faces let's just even that out a little bit more okay and that'll do for a little test so let's go back into object mode and go over to our modifiers now if you're looking to kind of build your final piece here and you're getting ready to extract normal or displacement maps you'll want to use a multi-res modifier but i found that the multi-res and the mirror modifier don't play particularly well with each other the mirror modifier can kind of break the multi-res so if you're just looking to test it and not do your final piece ignore the multi-resolution for now go and add a subdivision surface now you want to make sure that your subdivision is above your shrink wrap and you can see that we now start to get a little bit of additional detail in here so if we go to our viewport levels and we just kind of crank that up you can see that we can start to get some stuff happening here we can start to pull out some detail i'm going to go to about level four now you can probably also see that we're getting a little bit of weirdness going through here again i feel like this is something that the shrink wrap modifier can kind of mess up a little bit so i'm going to turn off my subdivision for a moment i'm going to come down here and i'm going to again apply our shrink wrap modifier and you can see that that's kind of missed just a couple of little things up again again that center line is just looking a little bit weird i'm going to use my grab tool and just make sure that all of that is aligning properly so now i'm going to go and turn our subdivision back on don't worry too much about this poking through we're going to fix that by applying reapplying our shrink wrap modifier and in this case i'll just rebuild this from scratch go with project above surface positive and negative just give it a tiny little bit of offset and you can see that most of that strangeness that was there before has now disappeared we're still getting a little bit maybe these vertices could be aligned a little bit better but we also just want to go right click and smooth shade and you can see that now this is starting to pick up pretty much all of our detail and depending on how detailed your model is you may want to go a little bit higher but this is really really good for just testing whether this is working whether you've got the right topology to start picking up these details and in this case it looks like we do we're just going to turn our wireframe back on you can see that some of these vertices aren't lining up perfectly so maybe we can go back in and tweak those but broadly speaking we've got some much much nicer topology here than what we had before now just as one final little tip it may be tempting to work to try and do your retopology while you've got the subdivision surface attached i would highly recommend not doing this and i'll just try to give you some examples you can see down here let's just go back to our poly build tool if i mouse over this you can see we've got this curved edge that's due to our subdivision surface this now makes it really hard to be able to tell exactly where our vertices are and we've got the same problem as we extrude out here you can see that that just kind of makes it even worse you can see that as i initially pull it out we get this really strange distortion happening that's because because of the subdivision modifier it's giving us you know a hundred more vertices than we can actually see here and then trying to use the shrink wrap as we drag it out it does kind of correct itself but well in that case it actually worked those those vertices snap together quite well but that's more of a coincidence than anything else you can see here i've got two faces these vertices haven't merged and now it's like well how do i actually get them to merge what am i grabbing i can eventually get it but this is a really kind of ugly way of working so i would strongly recommend not only disabling it but i'd in fact go as far to just delete the whole thing because it can kind of do some strange things to your shrink wrap in fact let's just pop this out a little bit further so we can see all this a bit better uh so strongly recommend not working with a subdivision applied get your mesh correct and then come in and create your subdivision after the fact and you can see that sometimes we still end up with a little bit of distortion so again let's just see if we can't duplicate that and apply the first one no it's not going to work for us we do actually need to delete the whole thing and recreate it from scratch and that helps us fix some of that strangeness except in the center here where it's still behaving a little bit strangely and there we go that's kind of fixed it so all of this is pretty good this i think proves that retopology in blender is is not only possible but it can be reasonably intuitive it's just that with all these things that can break particularly the shrink wrap modifier it can end up being a little bit slow because you have to kind of come in and apply the modifier and then recreate it it gets a little bit cumbersome as a little bit tricky so in the next lesson i'm going to introduce you to speedry topo which is an add-on it's free and it basically uses all of these tools and basically this methodology but it packages it all up into a nice user interface it makes applying and recreating these modifiers that much faster and just speeds up the entire process considerably so stick around for the next lesson and we'll go over speedry toppo

Channel: Jamie Dunbar

Views: 48,975

Keywords: Blender, retopology, dragon, spyro, polybuild, shrinkwrap, creature, tutorial, purple, Blender 2.9, remesh, topology

Id: l-sALvdn3FI

Length: 24min 14sec (1454 seconds)

Published: Fri Oct 30 2020